Stormwater is rainfall or melted snow that runs off impervious surfaces, such as rooftops, streets,
sidewalks, and parking lots. Impervious, or hard, surfaces prevent the stormwater from naturally
soaking into the ground, where the soil would filter out pollutants. As it flows, stormwater picks
up pollutants from these surfaces. Common pollutants include vehicle exhaust products, brake and
tire dust, oil and grease, sediment, salt, fertilizers and pesticides, pet waste, and litter. Because
stormwater is untreated, these pollutants enter our waterways.

Polluted stormwater runoff is a leading cause of impairment to almost 40% of water bodies in
the United States that do not meet water quality standards. When left uncontrolled, this water
pollution can result in the destruction of habitats for fish, wildlife, and aquatic life; a
loss in aesthetic value; and threats to public health because of contaminated food, drinking
water, and recreational waterways.

The National Pollutant Discharge Elimination System(NPDES) Stormwater Program is a comprehensive
water pollution reduction program that addresses stormwater discharges that impair the quality of our
nation's waters. Stormwater-regulated entities must obtain coverage under an NPDES stormwater permit
and implement stormwater management programs to effectively manage and reduce the discharge of
pollutants into local water bodies. Best management practices (BMPs) are methods (structural and
nonstructural) developed to lessen the impact of stormwater on the environment.

Phase I, established in 1990, regulated stormwater discharges for three types of activities: ten (10)
categories of industrial facilities, construction activities that disturb five (5) or more acres of
land, and municipal systems that serve populations of 100,000 people or more.

Phase II, which became law in 1999, requires smaller communities and operators of construction
activities that disturb one (1) to five (5) acres of land to reduce the discharge of pollutants,
protect water quality, and satisfy the requirements of the Clean Water Act.

Since 1970, NCDOT has been addressing stormwater pollution through
the Department's sediment and erosion control program. In 1998,
NCDOT established the Highway Stormwater Program (HSP) to address
other pollutants and sources associated with stormwater runoff.
NCDOT uses structural and nonstructural best management practices
(BMPs) to manage and reduce pollutants carried in stormwater. For
more information, slosh on over to the section entitled
NPDES Stormwater Permit.

Stormwater is an important issue throughout North Carolina. Under the direction of the Environmental
Management Commission, the following Department of Environment and Natural Resources Divisions regulate
stormwater: Division of Coastal Management, Division of Land Resources, and Division of Water Quality.
The US Environmental Protection Agency has delegated NPDES stormwater compliance responsibility to
NCDENR.